Memory map

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The Memory Map of the Next is based on the memory structure of the ZX Spectrum 128. The Z80's 16-bit bus can only access 64k of memory, laid out as follows:

  • $0000-$3999: ROM.
  • $4000-$7999: Screen. Depending on the video mode, not all of this RAM may be used for the screen. The remainder can be used freely but is slowed down by contention with the ULA drawing the screen. This is also bank 5.
  • $8000-$BFFF: Free RAM. This is also bank 2.
  • $C000-$FFFF: Switchable RAM bank.

The selected bank is set using Memory Paging Control ($7FFD / 32765).